Challenge 2 — Solution

Task: Given a string containing several prices like "Items: £12.50,
£3.99, and £100.00", use preg_match_all() with a capturing group to
extract just the numeric amounts (without the £ sign) into an array,
then use array_sum() to total them.

<?php
    $text = "Items: £12.50, £3.99, and £100.00";

    preg_match_all('/£(\d+\.\d{2})/', $text, $matches);
    print_r($matches[1]);

    $amounts = array_map('floatval', $matches[1]);
    echo "Total: £" . array_sum($amounts);
?>


Output:
Array
(
    [0] => 12.50
    [1] => 3.99
    [2] => 100.00
)
Total: £116.49

Notes:
- The pattern £(\d+\.\d{2}) matches a literal £ sign followed by one or
  more digits, a literal decimal point, and exactly two more digits -
  the parentheses around \d+\.\d{2} create a capturing group that
  excludes the £ sign itself from the captured text.
- $matches[1] (not $matches[0]) holds the captured group values -
  $matches[0] would instead hold the full matches including the £ sign
  each time, which array_sum() couldn't add directly.
- array_map('floatval', ...) converts each captured string (e.g.
  "12.50") into a real float before summing, since preg_match_all()
  always returns matched text as strings, and array_sum() needs actual
  numeric values to total correctly.